Coelenterata
Comb jellies (Beroe spp.)
Scientific classification
Kingdom: Animalia Subkingdom: Eumetazoa (unranked) Coelenterata
Phyla
Ctenophora Cnidaria Image File history File linksMetadata Size of this preview: 700 × 600 pixel Image in higher resolution (1564 × 1340 pixel, file size: 294 KB, MIME type: image/jpeg) This is a picture of two frolicking comb jellies (Beroe spp. ... Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Digimon, the only known animals. ... subgroups Ctenophora Cnidaria Bilateria Eumetazoa is a clade comprising all major animal groups except sponges. ... For the linguistic term, see Phylum (linguistics). ... Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ... Classes Anthozoa - Corals and sea anemones Scyphozoa - Jellyfish Staurozoa - Stalked jellyfish Cubozoa - Sea wasps or box jellyfish Polypodiozoa Hydrozoa - Hydroids, hydra-like animals Cnidaria[1] (IPA: [2]) is a phylum containing some 11,000 species of relatively simple animals found exclusively in aquatic, mostly marine, environments. ...

Coelenterata is an obsolete yet common term encompassing two animal phyla, the Ctenophora (comb jellies) and the Cnidaria (coral animals, true jellies, sea anemones, sea pens, and their allies). The taxon name comes from the Greek "koilos" ("hollow"), referring to the hollow body cavity common to these two phyla. They have very simple tissue organisation, with only two layers of cells, external and internal. Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ... Classes Anthozoa - Corals and sea anemones Scyphozoa - Jellyfish Staurozoa - Stalked jellyfish Cubozoa - Sea wasps or box jellyfish Polypodiozoa Hydrozoa - Hydroids, hydra-like animals Cnidaria[1] (IPA: [2]) is a phylum containing some 11,000 species of relatively simple animals found exclusively in aquatic, mostly marine, environments. ... Subclasses Alcyonaria Zoantharia See text for orders. ...

History of classification

The term coelenterate is no longer recognized as scientifically valid, as the Cnidaria and Ctenophora have placed at equal rank under the Metazoa with the other phyla of animals.^[1] A single term encompassing these two phyla but leaving out all others of equal rank would be considered polyphyletic. Nonetheless, the term coelenterate is still used in informal settings to refer to the Cnidaria and Ctenophora. Phyla Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented worms Tardigrada - Water bears Onychophora - Velvet worms Arthropoda - Insects, etc. ... In biology, a taxon is polyphyletic if it is descended from more than one root form (in Greek poly = many and phyletic = racial). ...

Complicating the issue is the 1997 work of Lynn Margulis (revising an earlier model by Thomas Cavalier-Smith) that placed the Cnidaria and Ctenophora alone under the Radiata branch of the Eumetazoa subregnum.^[2] (The latter refers to all the animals except the sponges, Trichoplax, and the still poorly-understood Mesozoa.) Neither grouping is accepted universally;^[3] however, both are commonly encountered in taxonomic literature. Lynn Margulis Dr. Lynn Margulis (born March 15, 1938) is a biologist and University Professor in the Department of Geosciences at the University of Massachusetts Amherst. ... Thomas Cavalier-Smith is a professor of evolutionary biology at the University of Oxford, and is winner of the International Prize for Biology 2004 and one of the most notable researchers concerning the relationships, development, and classification of living things. ... Phyla Cnidaria Ctenophora The Radiata are the radially symmetric animals of the Eumetazoa subregnum. ... subgroups Ctenophora Cnidaria Bilateria Eumetazoa is a clade comprising all major animal groups except sponges. ... The sponge, in the phylum Porifera, is a very primitive and specialized animal. ... Binomial name Trichoplax adhaerens F.E. von Schultze, 1883 Trichoplax adhaerens is a simple balloon-like marine animal with a body cavity filled with pressurized fluid. ... The Mesozoa are parasitic worm-like animals. ...

References

1. ^ Excerpt from Britannica article regarding Ctenophore classification
2. ^ Margulis, Lynn and Karlene V. Schwartz, 1997, Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, W.H. Freeman & Company, ISBN 0-613-92338-3
3. ^ NCBI Taxonomy Browser